Saturday, March 18, 2006
"A Neandertal (Homo neanderthalensis or Homo sapiens neanderthalensis) is a kind of human that lived in Europe and Western Asia until around 30,000 years ago. The first Neandertal skeleton was found by quarry workers in 1856 in the Neander Valley in Germany. At first people thought the odd-looking skeleton was that of a diseased person or of a Cossack from the Napoleonic War. It was only later, when similar remains were found in Belgium, that Neandertals became fully accepted as an extinct type of human. Since then, a debate about their relationship to modern humans has raged among paleontologists and geneticists, and inspired many writers of fiction."
"Recent research at the European Molecular Biology Laboratory (EMBL) reveals new insights into how cells achieve equality between the sexes. A new link discovered between the membrane surrounding the nucleus and the male X-chromosome in fruit flies may play a crucial role in determining how active certain genes are. The study, which appears in the current issue of the journal Molecular Cell, may help researchers understand how male and female cells manage to produce the same quantities of certain proteins."
"Earthly bacteria could have reached distant planets and moons after being flung into space by massive meteorite impacts, scientists suggest.
The proposal neatly reverses the panspermia theory, which suggests that life on Earth was seeded by microbes on comets or meteorites from elsewhere.
Both theories envision life spreading through the Solar System in much the same way that germs race around a crowded classroom, says Jeff Moore, a planetary scientist at NASA's Ames Research Center in Moffett Field, California. 'Once one planet comes down with life, they all get it.'"
"BUFFALO, N.Y. -- Researchers at the University at Buffalo and the University of Pennsylvania were the first to demonstrate that two intracellular events, both stimulated by the same cell receptor, can provoke different behaviors in mammals.
The broad implication of the findings may alter the way behavioral neuroscientists think about sub-cellular underpinnings of mammalian behavior, according to the researchers."
Friday, March 17, 2006
BBC News: "Workers redeveloping the site of a former steelworks near Wrexham have uncovered a fossil forest believed to date back 300 million years.
Geologists are now overseeing the excavation of the site, which is 50m long, at the old Brymbo works.
The forest pre-dated the dinosaurs and was from a time when what is now Wales was hot and humid and over the equator."
"It's said that Elvis Presley's love of fried peanut butter sandwiches started during his impoverished childhood, and the fat-soaked snack remained a favourite dish for the rest of his life. Locusts and Elvis could have something in common. In a study published in Science, Oxford researchers showed that the value given by locusts to a particular food depended on their condition at the time of eating it first.
The researchers set up trials to look at how organisms learn and on what basis they choose. They manipulated the preferences of the locusts: the insects met peppermint-flavoured grass when they were hungry and lemon-flavoured grass when they were not so hungry, and later behaved as if peppermint-flavoured grass was preferable. When they reversed the treatments, the locusts reversed their preference.
...This latest research into locusts suggests the point at which this mechanism may have been acquired could go even further back in evolutionary terms. It also casts light on why organisms sometimes don't seem to behave in an optimal or adaptive way."
"Humans appear to have lost what may have been a natural resistance to HIV some 7 million years when our bodies stopped producing particular kinds of protein, an Australian scientist says.
These circular proteins, called cyclotides, were discovered by Professor David Craik from the University of Queensland and colleagues, about 10 years ago.
Craik reports new insights into these molecules in the current issue of the journal Science.
The first cyclotide discovered in mammals, RTD1, was found in rhesus monkeys and when chemically synthesised acts against HIV."
When the American Museum of Natural History wanted to create a digital walking Tyrannosaurus rex for a new dinosaur exhibit, it turned to dinosaur locomotion experts John Hutchinson and Stephen Gatesy for guidance.
The pair found the process humbling.
With powerful computers and sophisticated modeling software, animators can take a pile of digital bones and move them in any way they want. This part is easy; but choosing the most likely motion from the myriad of possibilities proved difficult.
'We kind of took a step back and said 'Whoa, boy! Limbs are very complicated.' We can't just take a limb, connect the bones together and figure out how the animal moved,' Hutchinson told LiveScience. 'It's absolutely impossible.'
Clues to Mars life may lie underground: Scientist:
"Houston, Mar 17: To learn if Mars ever supported life, researchers should look underground, a scientist presenting results of the Mars Express mission said at a conference this week.
The European Space Agency's orbiter has mapped almost the entire planet for minerals that bear chemical fingerprints of past encounters with water.
Less than 1 percent of the planet's surface bears signs of hydrated minerals, said Jean-Pierre Bibring, the lead investigator for the Mars Express Omega instrument, which splits and analyzes visible and near-infrared light radiating from the planet's surface. "
Thursday, March 16, 2006
"BERKELEY - A lawsuit by a Roseville couple who claimed that a University of California, Berkeley, website used evolution to promote religion was dismissed Monday, March 13, in San Francisco federal court.
Without ruling on the merits of the suit, Judge Phyllis J. Hamilton of the U.S. District Court for the Northern District of California granted the University of California's motion to dismiss the case on the grounds that the plaintiffs lacked standing - that is, they did not have a sufficiently strong personal interest in the outcome of the case."
"Depending on which journals you've picked up in recent months, early humans were either peace-loving softies or war-mongering buffoons.
Which theory is to be believed?
A little bit of both, says one archaeologist, who warns against making generalizations when it comes to our long and varied prehistory.
The newest claim concerns Australopithecus afarensis, who lived approximately five million years ago and is one of the first hominids that can be linked directly to our lineage with some certainty. Hardly an expert at tearing other animals limb from limb, scientists say the small and furry creature likely spent most of its time avoiding becoming the lunch of those saber-toothed mammals you see in natural history museums today.
That's a far cry from the spear-wielding image most of the public has of our earliest ancestors, Robert Sussman of Washington University told an audience at the annual meeting of the American Association for the Advancement of Science last month."
The Times: Richard Dawkins looks back at the extraordinary 30-year history of his first book, The Selfish Gene:
"It is sobering to realise that I have lived nearly half my life with The Selfish Gene - for better, for worse. Over the years, as each subsequent book has appeared, publishers have sent me on tour to promote it. Audiences respond to the new book with gratifying enthusiasm, applaud politely and ask intelligent questions. Then they line up to buy, and have me sign . . . The Selfish Gene. That is a bit of an exaggeration. Some do buy the new book and, for the rest, my wife consoles me by arguing that people who newly discover an author will naturally tend to go back to his first book: having read The Selfish Gene, surely they'll work their way through to the latest and (to its fond parent) favourite baby?
I would mind more if I could claim that The Selfish Gene had become severely outmoded and superseded. Unfortunately (from one point of view) I cannot."
London Natural History Museum: "Scientists have shown it is possible to predict the colour of animals that are extinct.
Prof. Andrew Parker, scientist at the Natural History Museum, discovered that iridescent colours in animals result from tiny structures that show up under the microscope and these can be seen even in fossils of extinct animals.
...'I was looking at a scene of life, 515 million years old, depicted accurately in colour,' said Prof. Parker."
BBC News: "A rare Chinese frog has entered the record books as the first amphibian known to communicate using ultrasound.
Until now, only a few mammals - such as bats, whales and dolphins - have been found to use the very high frequency sound to contact each other.
The frog may have evolved the mechanism to be heard above the babble of running water, scientists tell this week's edition of the journal Nature.
The frog lives alongside fast-flowing streams in Anhui"
Wednesday, March 15, 2006
"Researchers studying strains of a lethal canine virus and a related human virus have determined why the canine virus was able to spread so quickly from cats to dogs, and then from sick dogs to healthy dogs. Their studies may lead to a new understanding of the critical molecular factors that permit viruses to jump from one species to another - information that could be helpful in assessing how much of a threat avian influenza is to humans.
In advance online publication of a paper in the April 2006 issue of the Journal of Virology, Laura Shackelton, an HHMI predoctoral fellow at the University of Oxford in England, examined the surprisingly rapid evolution of the B19 erythrovirus, a ubiquitous human parvovirus."
Turkey's chief organization of scientists has announced plans to investigate an ethical complaint against three U.K. researchers over a study of people who walk on all fours in Turkey.
The British scientists today broke weeks of silence on the issue to answer the complaints, saying they had done nothing wrong.
The comments came a day after a top U.K. expert in scientific ethics suggested a university where they work should investigate their research. [hand walking]
"OSLO (Reuters) - Exotic frogs and toads are dying out in the jungles of Latin America, apparent victims of global warming in what might be a harbinger of one of the worst waves of extinction since the dinosaurs.
Accelerating extinctions would derail a
United Nations goal of "a significant reduction in the current rate of biodiversity loss" by 2010. That target will be reviewed at a U.N. meeting of environment ministers in Curitiba, Brazil, on March 20-31.
"We are facing an extinction crisis," said Anne Larigauderie, head of Paris-based Diversitas which promotes research into life on the planet.
She estimated the rate of loss of all species was now 10-100 times faster than little-understood rates from fossil records. "
"NEW YORK - A 150 million-year-old fossil from southern Germany has paleontologists ruffled over how feathers arose in the line of dinosaurs that eventually produced birds.
The fossil is a juvenile carnivorous dinosaur about 2 1/2 feet long that paleontologists have named Juravenator for the Jura mountains in southern Germany where it was found.
It would have looked similar in life to the fleet-footed predators that menaced a young girl on the beach during the opening scene of The Lost World, the second Jurassic Park movie.
The fossil's exceptionally well-preserved bone structure clearly puts it among feathered kin on the dinosaur family tree."
Search for deep-sea vents nets new crab family:
"A blind white crab bristling with hairs has been wrested from the deep, named, and slotted into the family tree of crustaceans.
...Using Alvin, Segonzac had netted a white crab he thought might intrigue Jones from the periphery of a newfound hydrothermal vent.
'It was huge,' recalls Jones. 'It was seven inches long, and eyeless and hairy. We all realized it was really different, but we didn't have any specimens to compare it with, or DNA techniques on board to analyse it.' "
Sweat bees' social evolution
In the first study to link social evolution to climate change, Cornell University entomologists show that the social behavior of many species of sweat bees evolved simultaneously during a period of global warming.
This social evolution occurred much more recently than scientists ever thought - only 20 million to 22 million years ago, compared with the social evolution of other insects, which evolved more than 65 million years ago.
"We believe that climatic change was a critical factor in the evolution of social behavior in these bees," said Bryan Danforth, associate professor of entomology at Cornell. Sweat bees are eusocial, he explained, which is a type of social behavior in which the animals have permanently sterile worker castes (among other traits). Eusocial animals include honey, bumble, carpenter and sweat (halictid) bees, ants, termites, many wasps as well as certain kinds of shrimp and the naked mole rat.
Danforth's study , to be published in a forthcoming issue of the Proceedings of the Royal Society of London, Series B, Biological Sciences, used both fossils as well as more than 2,300 base pairs of DNA sequences from three genes to infer the evolutionary history, or phylogeny, of the family's eusocial lineages and their relatives. The DNA sequencing sheds light on how divergent the various species are from each other, and the fossils allow the researchers to represent the phylogeny in terms of a timeline in millions of years.
In 2002 and 2004, Danforth showed that the social evolution of the various species of halictid bees arose multiple times independently. The study on the timing of that social evolution, however, began as an honors thesis for former Cornell undergraduate Adam Pearson '03, now a graduate student at the University of Connecticut, in collaboration with Danforth and two former Cornell postdoctoral researchers, Sean Brady and Sedonia Sipes.
"What's so interesting is that the social behavior that's characteristic of these insects arose 'simultaneously,' that is, within 2 million years, which is a very narrow window in evolutionary terms," said Danforth. "It's also news to us that the origin of sociality in halictid bees was so recent."
Once the team dated the evolution of the social behaviors to just 20 million to 22 million years ago, they researched what might have been going on in this time frame that would trigger the development of social behavior in so many species at the same time.
"We discovered that the Earth underwent a warming trend from 15 to 26 million years ago," Danforth said. "In modern halictid bees, social behavior varies among species and even within species as a function of latitude and altitude such that species and populations at low latitudes and in warmer regions are often fully social, whereas they are solitary at higher latitudes and altitudes, which are colder."
Warmer regions have longer growing seasons, he explained, which allows two broods to emerge instead of one. The first brood (workers) helps raise the second brood (reproductives).
Danforth, who teaches Alien Empire: Bizarre Biology of Bugs (Entomology 201), a two-credit course in insect biology, and maintains a Web site on bee phylogeny, is also struck by the social flexibility of sweat bees.
"Other social insects (such as ants, termites, paper wasps and honey bees) have reached 'a point of no return' in social evolution in which members of the lineage are now unable to revert back to a solitary condition. These insects, however, seem to be able to revert fairly easily," he concluded.
Halictid bees, which are important native pollinators in the Northern Hemisphere, where there are about 1,000 species, are nicknamed sweat bees because they are attracted to the salts in human perspiration.
Source (adapted): Cornell University PR "The dating game: Social behavior of sweat bees evolved with Earth's warming a mere 20 million years ago, Cornell study finds" March 13 2006
Based on the paper:
Recent and simultaneous origins of eusociality in halictid bees
Sean G. Brady, Sedonia Sipes, Adam Pearson, and Bryan N. Danforth
Proceedings of the Royal Society B: Biological Sciences
ISSN: 0962-8452 (Paper) 1471-2954 (Online)
Issue: Volume 273, Number 1594 / July 07, 2006
Pages: 1643 - 1649
Eusocial organisms are characterized by cooperative brood care, generation overlap and reproductive division of labour. Traits associated with eusociality are most developed in ants, termites, paper wasps and corbiculate bees; the fossil record indicates that each of these advanced eusocial taxa evolved in the Late Cretaceous or earlier (greater than 65Myr ago). Halictid bees also include a large and diverse number of eusocial members, but, in contrast to advanced eusocial taxa, they are characterized by substantial intra- and inter-specific variation in social behaviour, which may be indicative of more recent eusocial evolution. To test this hypothesis, we used over 2400bp of DNA sequence data gathered from three protein-coding nuclear genes (opsin, wingless and EF-1a) to infer the phylogeny of eusocial halictid lineages and their relatives. Results from relaxed molecular clock dating techniques that utilize a combination of molecular and fossil data indicate that the three independent origins of eusociality in halictid bees occurred within a narrow time frame between approximately 20 and 22Myr ago. This relatively recent evolution helps to explain the pronounced levels of social variation observed within these bees. The three origins of eusociality appear to be temporally correlated with a period of global warming, suggesting that climate may have had an important role in the evolution and maintenance of eusociality in these bees.
Related posts include:
Tuesday, March 14, 2006
"After the verdict went against the teaching of intelligent design in schools in Dover, Pennsylvania, you could be forgiven for thinking that the argument for teaching creationism was on the decline (1). However, in the UK the educational establishment seems hell-bent on introducing those very same ideas into all state schools.
As reported in The Times (London) on Friday, the OCR examination board has included a comparative study of creationist views on evolution alongside those of Darwin (2). But should we be surprised to see ideas promoted by the religious right in the USA dished up to schoolkids in Britain?
Even a cursory look at the new science GCSE is enough to give anyone pause for thought. "
"If the history of life on Earth could be rewound and replayed, many of the same innovations would reappear, although at different times and in slightly different forms.
This is the conclusion of Geerat Vermeij, a paleontologist at the University of California, Davis.
Vermeij's views imply that evolution is in some ways predictable and that life on other planets might not be so alien after all.
'Some traits are so advantageous under so many circumstances, or arise so relatively easily by virtue of self-organization, that you're likely to see the same things again and again,' Vermeij told LiveScience.
Among the innovations that evolution might find irresistible: photosynthesis, plant seeds, mineralized bones, intelligence and language."
"The discovery in yeast cells of a genetic network that guards against lethal DNA damage is a first step in the creation of a database of disease-causing combinations of mutated human genes, according to researchers at The Johns Hopkins University School of Medicine led by Jef. D. Boeke, Ph.D. In a report in the March 10 issue of Cell, the Hopkins team described a genetic network that is necessary for ensuring genomic stability in yeast. This study also identified previously unrecognized genes critical for maintaining DNA integrity and novel functions for well-known genes.
'A lot of human diseases are caused by multiple gene mutations that are difficult to identify,' said Boeke, who is a professor of molecular biology and genetics and director of the High Throughput Biology Center at the Hopkins School of Medicine."
"When you're that old, you can call yourself anything you want.
A 75-million-year-old spider found near Lethbridge has been named after Alberta.
The spider, measuring only about one millimetre long, was found in the 1970s preserved in a piece of amber.
It was stored in a collection of fossils at the Royal Tyrrell Museum in Drumheller and examined in 2003 by visiting scientist David Penny of the University of Manchester, England.
The scientist determined it was a unique specimen and named in Orchestina Albertensis, after the province."
Monday, March 13, 2006
"Why is our cochlea, the key organ of hearing, curled into a spiral? It has been often thought to be a space-saving measure. But researchers in the United States have shown that the spiral could be vital for increasing our ear's sensitivity to sound, particularly at low frequencies.
Daphne Manoussaki of Vanderbilt University in Nashville, Tennessee, and her colleagues believe that the snail-shell curve of the cochlea focuses sound waves at the spiral's outer edge, making it easier for vibration-sensitive cells to detect them1.
If the researchers are right, then the ear is more sophisticated than we thought. "
"NEW YORK -- Charles Darwin, the father of evolutionary theory, was born to pious parents and raised a creationist. Stubborn and strong-headed, he hated school and did poorly, leading his despairing father to deride him as a dilettante who cared only for 'shooting, dogs, and rat catching.'
The prodigal son eventually found his way to Cambridge University, where he promised to hunker down and study for the clergy. It was here that he met the Rev. John Stevens Henslow, a renowned professor of science who nurtured Darwin's growing fascination with the natural world. In 1831, Henslow arranged for his charge to fill the post of 'unpaid naturalist' aboard the HMS Beagle, a 90-foot, two-masted Royal Navy ship embarking on a voyage around the world.
The rest is history -- a history on magisterial display through May at the Museum of Natural History in New York and then, from Feb. 18 to April 27, 2007, at the Boston Museum of Science."
"Intelligent design theory is creating quite a stir.
Most recently Kentucky Gov. Ernie Fletcher said he supported school boards teaching Intelligent Design. In December, a Pennsylvania judge ruled against a Dover Township school board decision to include the theory in text books, costing the taxpayers about a million dollars in legal fees. Movements to begin teaching the intelligent design theory have popped up in dozens of states forcing local legislators and courts to address the issue.
The concept is simple: Were humans created by some sort of intelligent designer, possibly a deity, or by did we evolve scientifically based on Charles Darwin's theories of natural selection?
However, as parents, school boards and taxpayers debate the larger issue, students locally have shared some interesting views..." [Evolution]
"...The new research on gene expression could provide an answer to a puzzle that has confounded biologists since Darwin and that has recently been seized on by proponents of intelligent design: the idea that life is too complex to have happened without the help of a higher being...
...'We need to understand how you get the various kinds of novelty -- the first hand, the first eye, the first brain,' said Marc Kirschner at a recent talk at Harvard Medical School, where he is a professor...
...The research on gene expression, and particularly an active field called 'evolutionary developmental biology,' or 'evo devo,' is now addressing this question"
Sunday, March 12, 2006
Comment and opinion from the Times and The Sunday Times (UK):
"THE FASHIONABLE notion that we're simply well-dressed cavemen - pinstripes and hair gel on the outside, grunting hunter-gatherer on the inside - has taken a clubbing.
Evolution didn't grind to a halt when we shed the loincloths - indeed, we are still evolving. Scientists at the University of Chicago have identified more than 700 new variants of genes that first appeared between 5,000 and 15,000 years ago. These spread rapidly among successive generations in particular populations and are involved in taste, smell, digestion, skin colour, hair texture and skeletal structure.
The change was prompted, it seems, by the shift from foraging to agriculture about 10,000 years ago."
"Saturn's tiny moon, Enceladus is brimming with liquid water and cannot be ruled out as a distant outpost of life. So say Cassini mission scientists after studying the geysers of ice particles and water vapour found spewing out of the moon’s south polar region in 2005.
Their analysis all but rules out the possibility that the plumes are caused by water ice sublimating directly into space. Instead the most likely scenario involves significant quantities of liquid water boiling off from near-surface reservoirs."
"EAST ASIAN and European cultures have long been very different, Richard E. Nisbett argued in his recent book 'The Geography of Thought.' East Asians tend to be more interdependent than the individualists of the West, which he attributed to the social constraints and central control handed down as part of the rice-farming techniques Asians have practiced for thousands of years.
A separate explanation for such long-lasting character traits may be emerging from the human genome. Humans have continued to evolve throughout prehistory and perhaps to the present day, according to a new analysis of the genome reported last week by Jonathan Pritchard, a population geneticist at the University of Chicago. So human nature may have evolved as well.
If so, scientists and historians say, a fresh look at history may be in order. Evolutionary changes in the genome could help explain cultural traits that last over many generations as societies adapted to different local pressures."
"Their affliction is like something out of a Victorian freak show. They crawl on hands and feet like animals, but with the swift agility of circus gymnasts. Their speech is a primitive babble.
But scientists believe these siblings from a Turkish family, apparently condemned to walk on all fours by a combination of birth defects, genetic damage and lack of medical care in infancy, may offer startling clues to the process of human evolution – and the days when our apelike ancestors first began to walk upright.
The Ulas family, who live in a remote Kurdish area of south-eastern Turkey, are the subject of a controversial new BBC program that features film footage of five brothers and sisters 'bear crawling' on their hands and feet.
And a Turkish scientist quoted by the program goes so far as to claim that the family are some kind of 'missing link' to our pre-human ancestors." [Uner Tan]
New York Times: "They will not be cloning sheep, engineering mutants or genetically modifying corn in the new biological research laboratory. And its ZIP code isn't in Berkeley, Cambridge or even Manhattan.
It's 10458 (sic), in the Bronx. The new $23 million facility - the first laboratory to be built at the New York Botanical Garden in 50 years - is expected to take genetic research at the nation's botanical gardens to a new level. Scholars at the new laboratory will be doing research into the ecology, habitat and biology of plants at a time when many species are increasingly endangered...
...Ultimately, said Dennis Stevenson, the garden's vice president for botanical science, some of its long-term research could provide answers to 'what Darwin called the abominable mystery - when, where and why flowering plants emerged.'"
"America's answer to Richard Dawkins is a self-confessed 'bright', his term for atheists, agnostics and defenders of Darwinism, a man who has made it his crusade to confront what he sees as the pernicious influence of the religious right in the United States. By Tim Adams.
Daniel Dennett has something of the look of those seventeenth-century puritan preachers who would talk for hours about the sins of the flesh. The gospel he has spent most of his life spreading, however, has nothing to do with supernatural vengeance; quite the opposite. His full white beard is worn more in homage to Charles Darwin than the Almighty.
When I went to see him at the little office in the corner of a quadrangle at Tufts University he has occupied for 30 years, he was examining on his computer screen the cover of his new book, Breaking the Spell. His book seeks to demonstrate that religion, chiefly Christianity, is itself a biologically evolved concept, and one that has outlived its usefulness. "
"Breaking the Spell: Religion as a Natural Phenomenon" is currently appearing on the 'Featured Books' page of the Evolution Book Store: UK | US or go directly to Amazon: UK | US